Targeted Ablation to Isolate Scar Channels Causing Ventricular Tachycardia

After standard VT induction and mapping procedures (noninvasive identification of induced VT exit sites with Vektor vMap; substrate mapping; initial pacemapping), the study will consist of pacing within the substrate and mapping all channel exits both noninvasively with vMap as well as invasively with high density mapping catheters within the heart by escape mapping (all paced sites creating a consistent paced morphology, up to the shortest stimulus-to-QRS interval achieved) as well as focal activation mapping of this channel exit while pacing within the channel. The noninvasive map will aid in focusing invasive mapping to a small area of the substrate. Once the exit sites are determined, ablation energy will be delivered based on the mapped exit sites in the substrate channel within 0.5cm of the exit with the goal of blocking each exit site mapped. After the ablation lesion set is delivered, repeat attempt to induce VT will be performed. If more VT is induced, additional ablation energy will be delivered guided by standard mapping techniques (substrate, slow conduction zones, pacemapping).

Inclusion criteria

• Patients with structural heart disease undergoing VT ablation

Exclusion criteria

• Unable or unwilling to sign consent
• Cardiogenic shock or NYHA Class IV heart failure and not a candidate for mechanical circulatory support for the procedure (percutaneous left ventricular assist device (LVAD), extracorporeal membrane oxygenation, or implanted LVAD)
• Absence of substrate during initial voltage mapping